CURLOPT_SSH_PRIVATE_KEYFILE(3) Library Functions Manual CURLOPT_SSH_PRIVATE_KEYFILE(3)

CURLOPT_SSH_PRIVATE_KEYFILE - private key file for SSH auth

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_PRIVATE_KEYFILE,
                          char *filename);

Pass a char pointer pointing to a filename for your private key. If not used, libcurl defaults to $HOME/.ssh/id_rsa or $HOME/.ssh/id_dsa if the HOME environment variable is set, and in the current directory if HOME is not set.

If the file is password-protected, set the password with CURLOPT_KEYPASSWD(3).

The SSH library derives the public key from this private key when possible. If the SSH library cannot derive the public key from the private one and no public one is provided with CURLOPT_SSH_PUBLIC_KEYFILE(3), the transfer fails.

The application does not have to keep the string around after setting this option.

As explained above

This functionality affects scp and sftp

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/file");
    curl_easy_setopt(curl, CURLOPT_SSH_PRIVATE_KEYFILE,
                     "/home/clarkkent/.ssh/id_rsa");
    curl_easy_setopt(curl, CURLOPT_KEYPASSWD, "password");
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

Added in curl 7.16.1

Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.

CURLOPT_SSH_AUTH_TYPES(3), CURLOPT_SSH_PUBLIC_KEYFILE(3)

2024-09-18 libcurl